In a photographic optical device, which is mounted on a cell phone or a digital camera, a laser beam pointer, or an optical instrument such as a portable projection display device or a projection display device for a car, a shake is easily occurred in its optical axis when a shake or external vibration is transmitted.
In order to prevent this problem, a photographic optical unit which is used, for example, in a portable photographic optical device has been proposed in which an actuator is structured on each of side faces of a movable module, and the movable module is swung around an X-axis and a Y-axis perpendicular to an optical axis direction (Z-axis direction) of the actuator on the basis of a detection result of a shake detection sensor to correct the shake (see Japanese Patent Laid-Open No. 2007-129295).
However, in a conventional optical unit, an angular velocity signal corresponding to a shake is integrated to obtain an angular displacement by a gyroscope which is used as a shake detection sensor and a movable module is displaced so as to correspond to the angular displacement and thus response of correction is not rapid. Further, when the shake correction is to be performed, an angle of the movable module is detected by another sensor to control a difference between a displacement and a command value to be zero. Therefore, the control system becomes complicated and the number of components including the sensor is increased.